This is the two-part episode that sought to be different from all other series episodes. From a production standpoint, it stands apart with the highest quality ever. The outdoor location shooting was a monumental challenge and resulted in the finest cinematography of any Gunsmoke episode ever shot. Indeed, that production value stands well above average today.
The two-part script allowed for deeper than normal character development, which was strange considering that only three principle cast members were present for the photography: James Arness, Ken Curtis, and Milburn Stone. It was just Matt, Festus, and Doc, surrounding by an unusually strong guest ensemble of veteran actors.
Ultimately, it is an episode that gives Dillon the chance to be the hero in a desperate bid to wire for help. That just ended up removing the one character perhaps strong enough to prevent the evolution of the central theme of the narrative. What happens when people desperate to live become willing to abandon honor for survival?
In this episode, the answer is that they are wiling to forego civilized behavior for mob rule, and become willing to sacrifice two of their own so that the others might escape.
Dillon returns just in time to end the standoff, but not before one man dies due to the desperate nature of the situation.
In the end, it comes down to a clash of cultures. Two men engage in a profit enterprise and cause death in a way they did not anticipate nor wanted. The Sioux tribe uses their own tribal sense of justice to hold a trainload of people hostage to get the two they believe guilty of harming their tribe. Two other men, guilty of something different, find out just how some are willing to abandon law and order to survive, and how easy it is for civilized behavior to devolve into the law of "club and fang."
Playing throughout both parts is a soaring theme composed by John Carl Parker, complete with several different arrangements played out to strike different moods. The music was quite effective.
Ultimately, this two-part episode was intended to rise to the level of a stand alone movie. In that regard, the 90 minutes of actual play (two hours counting commercial breaks) would have made a nice TV movie. Complete with end credits of the ensemble cast played out as a series of stills from the extended ending, and one understands how original this episode truly stood.
Only a series with such gravitas as Gunsmoke could have negotiated the production budget to pull this off, and it was a joy to watch.